Derivatives of 1,4,5,8-naphthalene tetracarboxylic acid and process of preparing it



Patented June 24, 1930 UNITED STATES WILHELM ECKERT AND HEINRICH GREUNE,OF ERANKFORT-ON DHEkMAIN HOCHST, GERMANY, ASSIGNOBS TO GENERAL ANILINEWORKS, INC., OF NEW YORK, N. Y.,

A. CORPORATION OF DELAWARE DERIVATIVES OF 1,4,5,8-NA.'PHTHALENETETRACARBOXYLIC ACID PROCESS OF PREPARING IT a 110 Drawing. Originalapplication filed January 27, 1927, Serial 1T0. 164,125, and in GermanyAugust 80, 1926. Divided and this application filed October 9, 1928.SerialNo. 311,414.

Our present invention relates to new derivatives of 1.4.5.8-naphthalenetetracarboxylic acid and to a process of preparing them.

We have found that by causing an orthodiamines compound to act upon thedianhydride of 1.4.5.8-naphthalenetetracarboxylic acid or upon the freeacid in the presence of a solvent of a low boiling point, such asalcohol or the like,-products are obtainable the constitution of whichis not exactly known. The said roducts can be converted into valuablevat yestufls by heating them in the dry state up to their boiling pointor by heating them .in the-presence of a solvent of a hi 'h boilingpoint.

The following example illustrates our invention but is not meant tolimit the invention thereto; the parts being by weight:

10 parts of the dianhydride of 1.4.5.8-naphthalenetetracarboxylic acid Iare heated to boiling on the reflux condenser in 50 parts of alcoholwith 8 parts of ortho-phenylenediamine. After some hours, the mass isfiltered by suction, washed with alcohol until the alcohol running offbecomes colorless and then dried.

The product thus obtained forms a brownish mass which, on addition ofconcentrated hydrochloric acid, yields a yellow sparingly solublehydrochloride. Said brownish mass dissolves in concentrated sulfuricacid to a yellowish-brown solution which when poured on water remainsgolden-yellow. It gives a wine-red leuco compound and dyes cotton veryweak orange tints.- probably the formula:

The product has 1(l parts of the condensation product thus Insteadoftreating the intermediate prod- Paar OFFECE uct in glacial acetic acid,it may also be heated alone in a dry state to about 150 0.

whereby it becomes deep-red and eliminates Water. Instead of glacialacetic acid, any

other solvent ordiluent of a high, boiling point may be used.

Thisapplicat1on 1s a division of our application Serial Number 16,125,filed January .In the following claimswe understandby the term1.4.5.8-naphthalenetetracarboxylic' acid compound not only, this aciditself, but

- also its anhydride and by the'term an ortho- I diamine compound we:understand the orthodiamines and the salts thereof.

Weclaimz 1. The process which comprises treating with an orthodiaminecompound 11.4.5.8- naphthalenetetracarboxylic acid. compound in thepresence of a diluent; at a temperature below 100 C. A

2. The process which comprises treating with an orthodiamine compoundthe compound of the following formula ll ll (888}, ll ll in the presenceof a diluent at a temperature below 100 C.

- 3. The process which comprises treatin with orthophenylenediamine thecompoun of the following formula:

in the presence of a diluent at a temperature below 100 C.

4. The process which comprises treating for some hours withorthophenylenediamine the compound of the folowing formula:

in the presence of boiling ethyl alcohol.

5. As a. new roduct the compound of the probable form a:

a i 8 i mil 3.

said product forming a brownish mass, yield- 0 ing on addition ofconcentrated hydrochloric acld a yellow sparingly soluble hydrochloride,dissolving in concentrated sulfuric acid to a yellowish-brown solutionwhich when poured on water remains clear golden-yellow, giving awine-red leuco compound, dyeing cotton very weak orange tints and being,when treated with boiling glacial acetic acid or other diluents orsolvents, having a boiling point more than 100 C. or when treated in adry state without using any solvent at a temperature higher than 100 C.converted into a red vat-dyestufl which yields a green leucocompound anddyes cotton deep-red tints. 6. As new products the compounds which areobtainable by heating an ortho-diamine compound with a1.4.5.8-naphthalene-tetracarboxylic acid compound in the presence of adiluent at a temperature below C.

In testimony whereof, we afiix our signa- 00 tures.

WILHELM ECKERT. HEINRICH GREUNE.

